Glow plug relay mod

[livn2play]

I am trying a resistor in to lengthen my glow plug cycle times. I have a 10ohm resitor and thought I have done everything the way it explains it in the manual. When I put the resistor I can't get my glow plugs to cycle, if I put a jumper wire inbetween the resistor they cycle, at the regular cycle time. What could I be doing wrong to not get a cycle when I put the resistor in? Could the controller be getting weak? I have an 1985 truck.
Any help would be greatly appreciated, I didn't think that such a simple mod. could be this frustrating.............

[More Power]

Originally posted by livn2play:
I am trying a resistor in to lengthen my glow plug cycle times. I have a 10ohm resitor and thought I have done everything the way it explains it in the manual. When I put the resistor I can't get my glow plugs to cycle, if I put a jumper wire inbetween the resistor they cycle, at the regular cycle time. What could I be doing wrong to not get a cycle when I put the resistor in? Could the controller be getting weak? I have an 1985 truck.
Any help would be greatly appreciated, I didn't think that such a simple mod. could be this frustrating............. Are you sure the resistor is 10 ohms? Is it a 2 watt or higher rated.

Jim

[snoman87]

Here is how mine looked ... installed the 10ohm 2watt and it works no problems. You must have something off.

My wire harness mod web page (http://www3.telus.net/gmc62td/engine_harness.htm)

[joed]

I'm thinking about doing this mod. as well to my recently acquired 82 6.2 (the orig. 82 controller died). In looking at the 85-93 glow system schematic, as an alternative, could you install a switch to send 12V to pin C after the controller's initial glow cycle to extend the time? This way you would have some manual control when longer times were needed?

Please forgive my electrical ignorance.

Thanks. Joe.

[livn2play]

The resistor is a 10ohm but I think the watts are higher, than a 2 watt. I am taking that this will make a difference? I guess my assumption was that the higher the watts the more load or current it could handle and the ohms creates more or less resistance. Let me know how the watt will affect the function of this mod.

[More Power]

The wattage spec is an indication of how much current flow the resistor can handle without damage. That wattage was determined during our tests when first developing the extended glow modification for the 1985-93 glow system.

When the glow system doesn't work with the resistor, but does without, I suspect the resistor value may be more than 10 ohms. A value of 5-10 seems to work fine.

Jim

[CleviteKid]

If you want to be exotic, do what I did, insert a NTC (negative temperature coefficient) thermistor in place of the resistor. It gets higher in resistance as the air gets colder. Glows longer cold than hot. Works like a charm.

Dr. Lee :cool: